Reamer



8, 1936, E. J. POHLMAN 2,063,753

REAMER Filed Sept. 27, 1952 Jase 23 I HIV/H/A/f; 75 a 3 1 INVENTOR 9 BY M M% v ATTORNEY UNITED STATES PATENT OFFICE REAMER Edward J. Pohhnan, Detroit, Mich. Application September 27, 1932, Serial No. 635,092

1 Claim.

The object of the invention is to provide a reamer in which both a roughing and finishing cut may be accomplished in one operation; to provide a reamer of the floating type which when used in a machine tool of a horizontal spindle will not tend to droop but will maintain its axial alignment with the shank; to provide a reamer yieldingly held in axial alignment with its shank; and generally to provide a combined roughing and finishing reamer which is of comparatively simple form and therefore susceptible of cheap manufacture.

With this object in view, the invention consists in a construction and combination of parts of which a preferred embodiment is illustrated in the accompanying drawing but to which embodiment the invention is not to be restricted. Continued use in practice may dictate certain changes or alterations and'the right is claimed to make any which fall within the scope of the annexed claim.

In the drawing:

Figure 1 is an elevational view, partly broken away, of a reamer constructed in accordance with the invention.

Figure 2 is an end elevational view.

Figures 3, 4, and 5 are sectional views on the planes indicated by the lines 3-3, 4-4 and 5-5 respectively of Figure 1.

Figure 6 is an elevational view of one of the roughing teeth and the immediately following finishing tooth.

The reamer is formed with a cylindrical body l0, fluted axially as indicated at H and I2, the former flutes being of a greater depth than the latter, so that a series of intercurrent roughing and finishing teeth l4 and I5 are provided. The finishing teeth l5 are formed with their faces lying in radial lines, but the roughing teeth are formed with their faces in planes at a slight angle to radial planes of the body and back of the radial plane of the preceding finishing teeth.

Both sets of teeth at the forward end of the body are chamfered at approximately the same angle, as indicated at l6 and 11, the chamfer on the end of the finishing teeth removing a greater amount of stock from them, so that the cutting edges at their forward extremities will be back of the forward cutting edges of the roughing teeth. It is anticipated that the roughing teeth will exceed the length of the finishing teeth by approximately one sixty-fourth of an inch, so that they will thus act as leaders for the finishing teeth, removing the bulk of the stock, so that the reamed hole will be brought to the proper dimensions by the cutting edges of the finishing teeth.

The roughing teeth are formed with their lands about one sixty-fourth of an inch wide and are backed off at an angle of approximately three 5 degrees. The lands I9 of the finishing teeth have a width of about one thirty-second of an inch (substantially twice the width of the roughing teeth) and are backed off at approximately a two degree angle.

The chamfered ends of the teeth, which are at approximately forty-five degree angles with the cutting edges of the teeth are backed off at an angle of approximately two degrees.

In radial extent, the finishing teeth are of course ground to the exact gauge of the reamer, while the radial extent of the roughing teeth is less than that of the finishing teeth by an amount which it is desired to leave as a finishing out.

In order that the reamer may be made of the floating type, so that it will readily enter the hole to be reamed, a universal connection between the shank 20 and the body of the reamer is effected, this universal connection comprising a coupling member 2| slotted in right-angularly related planes from oppostie ends to provide the pairs of spaced ears 22 and 23, of which the former pair of cars straddle an car 24 on the reamer body l0 and the latter straddle an car 25 formed on the shank 2i). Pins 26 and 21 extend through the sets of associated ears and complete the universal connection between the reamer and its shank.

In order that the reamer and shank may be yieldingly held in axial alignment, spring ribs 28 are employed, these being arranged axially of the 5 reamer and exterior to the coupling member 2|, being received in the ends of the pins 26 and 21 which are slotted, as indicated at 29, for this purpose. In order that the ribs may beretained tight against the shank and the reamer, a retainer rin 30 is employed, this ring being arranged in surrounding relation to the coupling member 2| to which it is secured by a radial screw 3 I, the latter passing through a body hole in the retainer ring and. threading into the coupling member 2 I.

The slots in the ends of the pins 26 and 21,

' maintain the axial position of the ribs 28 and the retainer ring 30 maintains them against the shank and the reamer body respectively, so that they function to yieldingly hold the reamer and the shank in axial alignment, permitting the universal joint connection to function, however, from any strain tending to deflect the reamer in the performance of a reaming operation. When the reamer is used in a horizontal spindle machine tool, the ribs prevent drooping at the forward end.

ishing teeth of which the faces of the latter are arranged in radial planes and the faces of the former in planes back of but at a slight angle to said radial planes.

EDWARD J. POHLMAN. 

